I don't really pay attention to what he says. If any of his arguments had merit, then I'm sure someone in the past 20 years would have published something about the M-E violating the laws of thermodynamics. His claims can probably be tracked to ignorance rather than anything concrete. After all, even very intelligent folks like John McKeever and Wheaton from ORNL ultimately didn't understand what they were critiquing. Just read Mahood's account of those events.AcesHigh wrote:and new GoatGuy rants, of course.
Mach Effect progress
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GIThruster
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Jim just posted his enormous 122 slide, end-of-season ppt a couple weeks ago. Nothing very new. The thrusts this last work season were the highest thus far, 10 uN, and as a reminder this is about 3 orders magnitude above what the ARC Lite balance can resolve; but no new data since that. he did some more tests to remove spurious concerns--same thing he's been doing for years. I think he's interested to look for higher thrusts next work season and of course his book should be out then too. The book has taken a lot of time this last season.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis
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GIThruster
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Thanks for the update! Looking forward to higher thrusts, maybe there will be more interest in replication after that.GIThruster wrote:Jim just posted his enormous 122 slide, end-of-season ppt a couple weeks ago. Nothing very new. The thrusts this last work season were the highest thus far, 10 uN, and as a reminder this is about 3 orders magnitude above what the ARC Lite balance can resolve; but no new data since that. he did some more tests to remove spurious concerns--same thing he's been doing for years. I think he's interested to look for higher thrusts next work season and of course his book should be out then too. The book has taken a lot of time this last season.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
Well GG, though I often agree with him, is underestimating the difficulties here.goatguy wrote: I think this is a perfect candidate for an oil-float table experiment. Its actually pretty straight forward: a large, circular, styrofoam-filled "boat" is floated on a non-volatile not overly viscous fluid, on a platform, in a near-vacuum. The test device is mounted on one side of the boat, a set of large batteries on the other. It is turned on, pointing tangentially (to make the boat go around).
If it turns full circles at all, then it should do so at an accelerating rate until some level of saturation is achieved. [The viscous counter-force of the oil is VERY easy to calculate from starting the thing moving without power, but with all the load, and measuring how long it takes to completely stop. Such rates then become very good measures of inertial effects.]
Let it run as long as the batteries allow. Remotely shut it off, and measure the spin-down. Carefully. Should follow save curve as the calibration step.
Then you have your real measure of Mach Effect. The circular motion also should cancel out directional systemic biases. The long time-of-operation helps dispense the idea that it "started out hot".
Self-contained means nothing outside can influence it, more or less.
Any such experiment has to deal with:
high freq electrostatic effects (1/r^2 - easily shieldable)
high freq magnetic effects ( 1/r^3 - not easily shieldable)
high freq electromagnetic effects (1/r^2 - easily shieldable)
Each of these will of course extend beyond the boat and interact with the oil, tray bottom & sides, etc.
We are concerned with interaction that can produce unidirectional thrust - that could be the case for electromagnetic, if currents are induced in anything conducting, for the others if there is any second order interaction through material nonlinearity.
So it is not obviously an isolated system.
Also the force generated is primarily a high intensity high frequency vibration, which can easily be rectified (interacting with any circular asymmetry in the oil bath, even the fact that the boat is not exactly central in the bath). There is no guarantee that could not happen in the oil due to some nonlinear effect. You need only a very tiny amount of such rectification to generate a false signal.
Jim, I know, takes some care to control for extraneous effects by changing various parameters in the system. E.g. altering electric vs mechanical phase, which should change M-E but not affect anything purely mechanical, or that relates to just electric or magnetic fields.
However, when you look at it, the possibilities for weird effects are difficult to rule out at such very small outputs, which is why I suspect Jim's results to be due to some such weird effect.
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GIThruster
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It's pretty often that people post in places like NBF simply trying to show how clever they are, and in effect show they're not familiar at all with the situation they're posting about. For instance, all the troubles Tom notes are removed by simply placing the self-contained test article on the ARC-Lite, so there's no point in the oil bath at all. At least the ARC-Lite is well characterized.
However, as I posted over at NBF, there are in addition a handful of issues that go with the notion of self-contained that GG hasn't concerned himself with. Here's what I posted there:
"Interesting experiment Goat is proposing but I would note that like many other proposals, you can't learn much with such an experiment. This is a typical response from engineers, that they focus on the notion of "self-contained' rather than on the need for scientific controls. What this sort of experiment gets you is just a binary answer--it works or it doesn't--but it doesn't get you useful information (unless you didn't know that it works, which Woodward does) and there are no controls. You can't tweek such a system over time to make it work or make it work better, because you neglected or misunderstood from the start what scientific controls are all about.
In the experiment Goat is suggesting, you can suppose no outside influence "more or less" which of course will turn out to be less. The reasons for self-containd then diminish as soon as you start to look at the details. OTOH, the reasons to power the device as Woodward has grow once you begin to look at the details of the experiment. For example, if you want to record data about what is happening with an M-E thruster, you first of all want to attach accelerometers so you can track the motion of the dielectric in real time. In a self-contained experiment, to have that data, you'd need to transmit it wirelessly and that's not an easy thing to do when you're driving high voltages at ultrasonic frequencies. This experiment Goat is proposing would have an enormous number of loose variables and opportunities for error--very much the opposite of the Woodward set-up where the vast majority of the possible variables are locked down. It would in effect be much more guilty of the kinds of experimental error Goat supposes are happening with Woodward's experimental setup.
And just to note--Goat was correct to be concerned with the details of Woodward's experiment. He was not correct to call into question the various possible sources of experimental error when he has not availed himself to understanding that setup.
Also note that any self-contained experiment would need to provide z-matching on the fly, as these devices go through impedance change as they heat up. These proposed experiments where one just turns on the device and lets it run are experiments that don't come to grips with the fact no one has yet developed the ultra-high speed z-matching and active feedback circuits necessary to continuous use. Designing, building and miniaturizing such a thing to run an experiment at this point in the research would be counter-productive. There are far too many other things worth doing first, like building the same power system for a device that is not miniaturized nor self-contained.
Just saying, it's easy to come up with objections to the experimental set-up and your own experiments, while you're ignorant of the facts. As soon as one becomes acquainted with the real challenges, one sees just how robust, flexible and capable Woodward's setup really is."
And just to address Tom's general concern, if Jim were producing 10mN thrusts which are certainly commercial grade thrusts comparable to those produced by standard Hall Thruster systems, one could still make the objection that these tiny thrusts could be spurious. No matter the thrust level, you need to eliminate all the various possibilities. That's why it's so important that Jim be able to provide vacuum, be able to shield, be able to rotate through various spacial orientations including off-axis on the balance so the thrust measured goes to zero.
While I understand with and generally agree with Tom's concerns about spurious sources, I think when you invest yourself in understanding the measurement setup, this puts those concerns to rest. I'd note too, one can get an excellent view of how the lab setup works in Jim's book soon to be published by Springer.
However, as I posted over at NBF, there are in addition a handful of issues that go with the notion of self-contained that GG hasn't concerned himself with. Here's what I posted there:
"Interesting experiment Goat is proposing but I would note that like many other proposals, you can't learn much with such an experiment. This is a typical response from engineers, that they focus on the notion of "self-contained' rather than on the need for scientific controls. What this sort of experiment gets you is just a binary answer--it works or it doesn't--but it doesn't get you useful information (unless you didn't know that it works, which Woodward does) and there are no controls. You can't tweek such a system over time to make it work or make it work better, because you neglected or misunderstood from the start what scientific controls are all about.
In the experiment Goat is suggesting, you can suppose no outside influence "more or less" which of course will turn out to be less. The reasons for self-containd then diminish as soon as you start to look at the details. OTOH, the reasons to power the device as Woodward has grow once you begin to look at the details of the experiment. For example, if you want to record data about what is happening with an M-E thruster, you first of all want to attach accelerometers so you can track the motion of the dielectric in real time. In a self-contained experiment, to have that data, you'd need to transmit it wirelessly and that's not an easy thing to do when you're driving high voltages at ultrasonic frequencies. This experiment Goat is proposing would have an enormous number of loose variables and opportunities for error--very much the opposite of the Woodward set-up where the vast majority of the possible variables are locked down. It would in effect be much more guilty of the kinds of experimental error Goat supposes are happening with Woodward's experimental setup.
And just to note--Goat was correct to be concerned with the details of Woodward's experiment. He was not correct to call into question the various possible sources of experimental error when he has not availed himself to understanding that setup.
Also note that any self-contained experiment would need to provide z-matching on the fly, as these devices go through impedance change as they heat up. These proposed experiments where one just turns on the device and lets it run are experiments that don't come to grips with the fact no one has yet developed the ultra-high speed z-matching and active feedback circuits necessary to continuous use. Designing, building and miniaturizing such a thing to run an experiment at this point in the research would be counter-productive. There are far too many other things worth doing first, like building the same power system for a device that is not miniaturized nor self-contained.
Just saying, it's easy to come up with objections to the experimental set-up and your own experiments, while you're ignorant of the facts. As soon as one becomes acquainted with the real challenges, one sees just how robust, flexible and capable Woodward's setup really is."
And just to address Tom's general concern, if Jim were producing 10mN thrusts which are certainly commercial grade thrusts comparable to those produced by standard Hall Thruster systems, one could still make the objection that these tiny thrusts could be spurious. No matter the thrust level, you need to eliminate all the various possibilities. That's why it's so important that Jim be able to provide vacuum, be able to shield, be able to rotate through various spacial orientations including off-axis on the balance so the thrust measured goes to zero.
While I understand with and generally agree with Tom's concerns about spurious sources, I think when you invest yourself in understanding the measurement setup, this puts those concerns to rest. I'd note too, one can get an excellent view of how the lab setup works in Jim's book soon to be published by Springer.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis
I don't pay attention to "Goat Guy", especially with regards to the Woodward-Mach stuff . From what I've seen, Woodward has done very careful experimentation and has definitively ruled out spurulous effects as a cause. The key now if if he can scale up the effect such that it is consistant with his equations. If he can, the effect is real as far as I'm concerned. It then becomes an engineering matter.
I hope you're right, but I don't think his work will get recognition until he's scaled it to the point of irrefutable (IE: floating himself into a conference) Now that would be a sight. Anywho, I hope he has something and I hope it's huge....I'd like to potentially see the stars some day.kurt9 wrote:I don't pay attention to "Goat Guy", especially with regards to the Woodward-Mach stuff . From what I've seen, Woodward has done very careful experimentation and has definitively ruled out spurulous effects as a cause. The key now if if he can scale up the effect such that it is consistant with his equations. If he can, the effect is real as far as I'm concerned. It then becomes an engineering matter.
Wasn't there a link here recently to a page authored by one of Woodward's central people, who reported that the mass signal was zeroing out as instruments became more sensitive?ScottL wrote:I hope you're right, but I don't think his work will get recognition until he's scaled it to the point of irrefutable (IE: floating himself into a conference) Now that would be a sight. Anywho, I hope he has something and I hope it's huge....I'd like to potentially see the stars some day.kurt9 wrote:I don't pay attention to "Goat Guy", especially with regards to the Woodward-Mach stuff . From what I've seen, Woodward has done very careful experimentation and has definitively ruled out spurulous effects as a cause. The key now if if he can scale up the effect such that it is consistant with his equations. If he can, the effect is real as far as I'm concerned. It then becomes an engineering matter.
I.e. the Mach-Effect devices are, unfortunately, a new way to pull off a Dean Drive effect.
Vae Victis
That was Tom Mahood and, yes indeed, he said the experimental results got smaller as more precise experiments were done. It would be enough to write off the concept, except that Woodward has done a more recent set of experiments to eliminate any potential errors and spurulous effects and yet the effect has remained. The magnitude does not fit with his equations and he is doing a new set of experiments to determine why.
If M-E exists, at any level, it has major consequences and practical applications.
Those who read Jim's experiments, notice that he is careful to control errors, and say therefore the effect must be real underestimate the problems.
For every effect controlled there will be another one (perhaps involving some extra phase shift, or unexpected nonlinearity) not considered. If people are interested and Jim's latest stuff is postable we could go nthrough it attempting to find the gaps.
All this stuff is relevant at very low output levels. At higher level you can rule out a lot of the second order stuff etc because it would be too small.
You can't do any of this analysis without very carefully going through all the details, so what I'm saying is my memory of when I last went through Jim's stuff. But the fact that over time, in spite of higher theoretical output experiments, the observed output has gone down must make experimental error here most likely even if the precise mechanism is not easy to tease out.
Those who read Jim's experiments, notice that he is careful to control errors, and say therefore the effect must be real underestimate the problems.
For every effect controlled there will be another one (perhaps involving some extra phase shift, or unexpected nonlinearity) not considered. If people are interested and Jim's latest stuff is postable we could go nthrough it attempting to find the gaps.
All this stuff is relevant at very low output levels. At higher level you can rule out a lot of the second order stuff etc because it would be too small.
You can't do any of this analysis without very carefully going through all the details, so what I'm saying is my memory of when I last went through Jim's stuff. But the fact that over time, in spite of higher theoretical output experiments, the observed output has gone down must make experimental error here most likely even if the precise mechanism is not easy to tease out.